---
title: Gateway
description: Configuration affecting edge load balancer.
location: https://istio.io/docs/reference/config/networking/gateway.html
layout: protoc-gen-docs
generator: protoc-gen-docs
schema: istio.networking.v1alpha3.Gateway
aliases: [/docs/reference/config/networking/v1alpha3/gateway]
number_of_entries: 6
---
<p><code>Gateway</code> describes a load balancer operating at the edge of the mesh
receiving incoming or outgoing HTTP/TCP connections. The specification
describes a set of ports that should be exposed, the type of protocol to
use, SNI configuration for the load balancer, etc.</p>
<p>For example, the following Gateway configuration sets up a proxy to act
as a load balancer exposing port 80 and 9080 (http), 443 (https),
9443(https) and port 2379 (TCP) for ingress.  The gateway will be
applied to the proxy running on a pod with labels <code>app: my-gateway-controller</code>. While Istio will configure the proxy to listen
on these ports, it is the responsibility of the user to ensure that
external traffic to these ports are allowed into the mesh.</p>
<p>{{<tabset category-name="example">}}
{{<tab name="v1alpha3" category-value="v1alpha3">}}</p>
<pre><code class="language-yaml">apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: my-gateway
  namespace: some-config-namespace
spec:
  selector:
    app: my-gateway-controller
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - uk.bookinfo.com
    - eu.bookinfo.com
    tls:
      httpsRedirect: true # sends 301 redirect for http requests
  - port:
      number: 443
      name: https-443
      protocol: HTTPS
    hosts:
    - uk.bookinfo.com
    - eu.bookinfo.com
    tls:
      mode: SIMPLE # enables HTTPS on this port
      serverCertificate: /etc/certs/servercert.pem
      privateKey: /etc/certs/privatekey.pem
  - port:
      number: 9443
      name: https-9443
      protocol: HTTPS
    hosts:
    - &quot;bookinfo-namespace/*.bookinfo.com&quot;
    tls:
      mode: SIMPLE # enables HTTPS on this port
      credentialName: bookinfo-secret # fetches certs from Kubernetes secret
  - port:
      number: 9080
      name: http-wildcard
      protocol: HTTP
    hosts:
    - &quot;*&quot;
  - port:
      number: 2379 # to expose internal service via external port 2379
      name: mongo
      protocol: MONGO
    hosts:
    - &quot;*&quot;
</code></pre>
<p>{{</tab>}}</p>
<p>{{<tab name="v1beta1" category-value="v1beta1">}}</p>
<pre><code class="language-yaml">apiVersion: networking.istio.io/v1beta1
kind: Gateway
metadata:
  name: my-gateway
  namespace: some-config-namespace
spec:
  selector:
    app: my-gateway-controller
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - uk.bookinfo.com
    - eu.bookinfo.com
    tls:
      httpsRedirect: true # sends 301 redirect for http requests
  - port:
      number: 443
      name: https-443
      protocol: HTTPS
    hosts:
    - uk.bookinfo.com
    - eu.bookinfo.com
    tls:
      mode: SIMPLE # enables HTTPS on this port
      serverCertificate: /etc/certs/servercert.pem
      privateKey: /etc/certs/privatekey.pem
  - port:
      number: 9443
      name: https-9443
      protocol: HTTPS
    hosts:
    - &quot;bookinfo-namespace/*.bookinfo.com&quot;
    tls:
      mode: SIMPLE # enables HTTPS on this port
      credentialName: bookinfo-secret # fetches certs from Kubernetes secret
  - port:
      number: 9080
      name: http-wildcard
      protocol: HTTP
    hosts:
    - &quot;*&quot;
  - port:
      number: 2379 # to expose internal service via external port 2379
      name: mongo
      protocol: MONGO
    hosts:
    - &quot;*&quot;
</code></pre>
<p>{{</tab>}}
{{</tabset>}}</p>
<p>The Gateway specification above describes the L4-L6 properties of a load
balancer. A <code>VirtualService</code> can then be bound to a gateway to control
the forwarding of traffic arriving at a particular host or gateway port.</p>
<p>For example, the following VirtualService splits traffic for
<code>https://uk.bookinfo.com/reviews</code>, <code>https://eu.bookinfo.com/reviews</code>,
<code>http://uk.bookinfo.com:9080/reviews</code>,
<code>http://eu.bookinfo.com:9080/reviews</code> into two versions (prod and qa) of
an internal reviews service on port 9080. In addition, requests
containing the cookie &ldquo;user: dev-123&rdquo; will be sent to special port 7777
in the qa version. The same rule is also applicable inside the mesh for
requests to the &ldquo;reviews.prod.svc.cluster.local&rdquo; service. This rule is
applicable across ports 443, 9080. Note that <code>http://uk.bookinfo.com</code>
gets redirected to <code>https://uk.bookinfo.com</code> (i.e. 80 redirects to 443).</p>
<p>{{<tabset category-name="example">}}
{{<tab name="v1alpha3" category-value="v1alpha3">}}</p>
<pre><code class="language-yaml">apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: bookinfo-rule
  namespace: bookinfo-namespace
spec:
  hosts:
  - reviews.prod.svc.cluster.local
  - uk.bookinfo.com
  - eu.bookinfo.com
  gateways:
  - some-config-namespace/my-gateway
  - mesh # applies to all the sidecars in the mesh
  http:
  - match:
    - headers:
        cookie:
          exact: &quot;user=dev-123&quot;
    route:
    - destination:
        port:
          number: 7777
        host: reviews.qa.svc.cluster.local
  - match:
    - uri:
        prefix: /reviews/
    route:
    - destination:
        port:
          number: 9080 # can be omitted if it's the only port for reviews
        host: reviews.prod.svc.cluster.local
      weight: 80
    - destination:
        host: reviews.qa.svc.cluster.local
      weight: 20
</code></pre>
<p>{{</tab>}}</p>
<p>{{<tab name="v1beta1" category-value="v1beta1">}}</p>
<pre><code class="language-yaml">apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: bookinfo-rule
  namespace: bookinfo-namespace
spec:
  hosts:
  - reviews.prod.svc.cluster.local
  - uk.bookinfo.com
  - eu.bookinfo.com
  gateways:
  - some-config-namespace/my-gateway
  - mesh # applies to all the sidecars in the mesh
  http:
  - match:
    - headers:
        cookie:
          exact: &quot;user=dev-123&quot;
    route:
    - destination:
        port:
          number: 7777
        host: reviews.qa.svc.cluster.local
  - match:
    - uri:
        prefix: /reviews/
    route:
    - destination:
        port:
          number: 9080 # can be omitted if it's the only port for reviews
        host: reviews.prod.svc.cluster.local
      weight: 80
    - destination:
        host: reviews.qa.svc.cluster.local
      weight: 20
</code></pre>
<p>{{</tab>}}
{{</tabset>}}</p>
<p>The following VirtualService forwards traffic arriving at (external)
port 27017 to internal Mongo server on port 5555. This rule is not
applicable internally in the mesh as the gateway list omits the
reserved name <code>mesh</code>.</p>
<p>{{<tabset category-name="example">}}
{{<tab name="v1alpha3" category-value="v1alpha3">}}</p>
<pre><code class="language-yaml">apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: bookinfo-mongo
  namespace: bookinfo-namespace
spec:
  hosts:
  - mongosvr.prod.svc.cluster.local # name of internal Mongo service
  gateways:
  - some-config-namespace/my-gateway # can omit the namespace if gateway is in same namespace as virtual service.
  tcp:
  - match:
    - port: 27017
    route:
    - destination:
        host: mongo.prod.svc.cluster.local
        port:
          number: 5555
</code></pre>
<p>{{</tab>}}</p>
<p>{{<tab name="v1beta1" category-value="v1beta1">}}</p>
<pre><code class="language-yaml">apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: bookinfo-mongo
  namespace: bookinfo-namespace
spec:
  hosts:
  - mongosvr.prod.svc.cluster.local # name of internal Mongo service
  gateways:
  - some-config-namespace/my-gateway # can omit the namespace if gateway is in same namespace as virtual service.
  tcp:
  - match:
    - port: 27017
    route:
    - destination:
        host: mongo.prod.svc.cluster.local
        port:
          number: 5555
</code></pre>
<p>{{</tab>}}
{{</tabset>}}</p>
<p>It is possible to restrict the set of virtual services that can bind to
a gateway server using the namespace/hostname syntax in the hosts field.
For example, the following Gateway allows any virtual service in the ns1
namespace to bind to it, while restricting only the virtual service with
foo.bar.com host in the ns2 namespace to bind to it.</p>
<p>{{<tabset category-name="example">}}
{{<tab name="v1alpha3" category-value="v1alpha3">}}</p>
<pre><code class="language-yaml">apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: my-gateway
  namespace: some-config-namespace
spec:
  selector:
    app: my-gateway-controller
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - &quot;ns1/*&quot;
    - &quot;ns2/foo.bar.com&quot;
</code></pre>
<p>{{</tab>}}</p>
<p>{{<tab name="v1beta1" category-value="v1beta1">}}</p>
<pre><code class="language-yaml">apiVersion: networking.istio.io/v1beta1
kind: Gateway
metadata:
  name: my-gateway
  namespace: some-config-namespace
spec:
  selector:
    app: my-gateway-controller
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - &quot;ns1/*&quot;
    - &quot;ns2/foo.bar.com&quot;
</code></pre>
<p>{{</tab>}}
{{</tabset>}}</p>

<h2 id="Gateway">Gateway</h2>
<section>
<p>Gateway describes a load balancer operating at the edge of the mesh
receiving incoming or outgoing HTTP/TCP connections.</p>

<table class="message-fields">
<thead>
<tr>
<th>Field</th>
<th>Type</th>
<th>Description</th>
<th>Required</th>
</tr>
</thead>
<tbody>
<tr id="Gateway-servers">
<td><code>servers</code></td>
<td><code><a href="#Server">Server[]</a></code></td>
<td>
<p>A list of server specifications.</p>

</td>
<td>
Yes
</td>
</tr>
<tr id="Gateway-selector">
<td><code>selector</code></td>
<td><code>map&lt;string,&nbsp;string&gt;</code></td>
<td>
<p>One or more labels that indicate a specific set of pods/VMs
on which this gateway configuration should be applied.
By default workloads are searched across all namespaces based on label selectors.
This implies that a gateway resource in the namespace &ldquo;foo&rdquo; can select pods in
the namespace &ldquo;bar&rdquo; based on labels.
This behavior can be controlled via the <code>PILOT_SCOPE_GATEWAY_TO_NAMESPACE</code>
environment variable in istiod. If this variable is set
to true, the scope of label search is restricted to the configuration
namespace in which the the resource is present. In other words, the Gateway
resource must reside in the same namespace as the gateway workload
instance.
If selector is nil, the Gateway will be applied to all workloads.</p>

</td>
<td>
Yes
</td>
</tr>
</tbody>
</table>
</section>
<h2 id="Server">Server</h2>
<section>
<p><code>Server</code> describes the properties of the proxy on a given load balancer
port. For example,</p>
<p>{{<tabset category-name="example">}}
{{<tab name="v1alpha3" category-value="v1alpha3">}}</p>
<pre><code class="language-yaml">apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: my-ingress
spec:
  selector:
    app: my-ingressgateway
  servers:
  - port:
      number: 80
      name: http2
      protocol: HTTP2
    hosts:
    - &quot;*&quot;
</code></pre>
<p>{{</tab>}}</p>
<p>{{<tab name="v1beta1" category-value="v1beta1">}}</p>
<pre><code class="language-yaml">apiVersion: networking.istio.io/v1beta1
kind: Gateway
metadata:
  name: my-ingress
spec:
  selector:
    app: my-ingressgateway
  servers:
  - port:
      number: 80
      name: http2
      protocol: HTTP2
    hosts:
    - &quot;*&quot;
</code></pre>
<p>{{</tab>}}
{{</tabset>}}</p>
<p>Another example</p>
<p>{{<tabset category-name="example">}}
{{<tab name="v1alpha3" category-value="v1alpha3">}}</p>
<pre><code class="language-yaml">apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: my-tcp-ingress
spec:
  selector:
    app: my-tcp-ingressgateway
  servers:
  - port:
      number: 27018
      name: mongo
      protocol: MONGO
    hosts:
    - &quot;*&quot;
</code></pre>
<p>{{</tab>}}</p>
<p>{{<tab name="v1beta1" category-value="v1beta1">}}</p>
<pre><code class="language-yaml">apiVersion: networking.istio.io/v1beta1
kind: Gateway
metadata:
  name: my-tcp-ingress
spec:
  selector:
    app: my-tcp-ingressgateway
  servers:
  - port:
      number: 27018
      name: mongo
      protocol: MONGO
    hosts:
    - &quot;*&quot;
</code></pre>
<p>{{</tab>}}
{{</tabset>}}</p>
<p>The following is an example of TLS configuration for port 443</p>
<p>{{<tabset category-name="example">}}
{{<tab name="v1alpha3" category-value="v1alpha3">}}</p>
<pre><code class="language-yaml">apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: my-tls-ingress
spec:
  selector:
    app: my-tls-ingressgateway
  servers:
  - port:
      number: 443
      name: https
      protocol: HTTPS
    hosts:
    - &quot;*&quot;
    tls:
      mode: SIMPLE
      credentialName: tls-cert
</code></pre>
<p>{{</tab>}}</p>
<p>{{<tab name="v1beta1" category-value="v1beta1">}}</p>
<pre><code class="language-yaml">apiVersion: networking.istio.io/v1beta1
kind: Gateway
metadata:
  name: my-tls-ingress
spec:
  selector:
    app: my-tls-ingressgateway
  servers:
  - port:
      number: 443
      name: https
      protocol: HTTPS
    hosts:
    - &quot;*&quot;
    tls:
      mode: SIMPLE
      credentialName: tls-cert
</code></pre>
<p>{{</tab>}}
{{</tabset>}}</p>

<table class="message-fields">
<thead>
<tr>
<th>Field</th>
<th>Type</th>
<th>Description</th>
<th>Required</th>
</tr>
</thead>
<tbody>
<tr id="Server-port">
<td><code>port</code></td>
<td><code><a href="#Port">Port</a></code></td>
<td>
<p>The Port on which the proxy should listen for incoming
connections.</p>

</td>
<td>
Yes
</td>
</tr>
<tr id="Server-bind">
<td><code>bind</code></td>
<td><code>string</code></td>
<td>
<p>The ip or the Unix domain socket to which the listener should be bound
to. Format: <code>x.x.x.x</code> or <code>unix:///path/to/uds</code> or <code>unix://@foobar</code>
(Linux abstract namespace). When using Unix domain sockets, the port
number should be 0.
This can be used to restrict the reachability of this server to be gateway internal only.
This is typically used when a gateway needs to communicate to another mesh service
e.g. publishing metrics. In such case, the server created with the
specified bind will not be available to external gateway clients.</p>

</td>
<td>
No
</td>
</tr>
<tr id="Server-hosts">
<td><code>hosts</code></td>
<td><code>string[]</code></td>
<td>
<p>One or more hosts exposed by this gateway.
While typically applicable to
HTTP services, it can also be used for TCP services using TLS with SNI.
A host is specified as a <code>dnsName</code> with an optional <code>namespace/</code> prefix.
The <code>dnsName</code> should be specified using FQDN format, optionally including
a wildcard character in the left-most component (e.g., <code>prod/*.example.com</code>).
Set the <code>dnsName</code> to <code>*</code> to select all <code>VirtualService</code> hosts from the
specified namespace (e.g.,<code>prod/*</code>).</p>
<p>The <code>namespace</code> can be set to <code>*</code> or <code>.</code>, representing any or the current
namespace, respectively. For example, <code>*/foo.example.com</code> selects the
service from any available namespace while <code>./foo.example.com</code> only selects
the service from the namespace of the sidecar. The default, if no <code>namespace/</code>
is specified, is <code>*/</code>, that is, select services from any namespace.
Any associated <code>DestinationRule</code> in the selected namespace will also be used.</p>
<p>A <code>VirtualService</code> must be bound to the gateway and must have one or
more hosts that match the hosts specified in a server. The match
could be an exact match or a suffix match with the server&rsquo;s hosts. For
example, if the server&rsquo;s hosts specifies <code>*.example.com</code>, a
<code>VirtualService</code> with hosts <code>dev.example.com</code> or <code>prod.example.com</code> will
match. However, a <code>VirtualService</code> with host <code>example.com</code> or
<code>newexample.com</code> will not match.</p>
<p>NOTE: Only virtual services exported to the gateway&rsquo;s namespace
(e.g., <code>exportTo</code> value of <code>*</code>) can be referenced.
Private configurations (e.g., <code>exportTo</code> set to <code>.</code>) will not be
available. Refer to the <code>exportTo</code> setting in <code>VirtualService</code>,
<code>DestinationRule</code>, and <code>ServiceEntry</code> configurations for details.</p>

</td>
<td>
Yes
</td>
</tr>
<tr id="Server-tls">
<td><code>tls</code></td>
<td><code><a href="#ServerTLSSettings">ServerTLSSettings</a></code></td>
<td>
<p>Set of TLS related options that govern the server&rsquo;s behavior. Use
these options to control if all http requests should be redirected to
https, and the TLS modes to use.</p>

</td>
<td>
No
</td>
</tr>
<tr id="Server-name">
<td><code>name</code></td>
<td><code>string</code></td>
<td>
<p>An optional name of the server, when set must be unique across all servers.
This will be used for variety of purposes like prefixing stats generated with
this name etc.</p>

</td>
<td>
No
</td>
</tr>
</tbody>
</table>
</section>
<h2 id="Port">Port</h2>
<section>
<p>Port describes the properties of a specific port of a service.</p>

<table class="message-fields">
<thead>
<tr>
<th>Field</th>
<th>Type</th>
<th>Description</th>
<th>Required</th>
</tr>
</thead>
<tbody>
<tr id="Port-number">
<td><code>number</code></td>
<td><code>uint32</code></td>
<td>
<p>A valid non-negative integer port number.</p>

</td>
<td>
Yes
</td>
</tr>
<tr id="Port-protocol">
<td><code>protocol</code></td>
<td><code>string</code></td>
<td>
<p>The protocol exposed on the port.
MUST BE one of HTTP|HTTPS|GRPC|HTTP2|MONGO|TCP|TLS.
TLS can be either used to terminate non-HTTP based connections on a specific port
or to route traffic based on SNI header to the destination without terminating the TLS connection.</p>

</td>
<td>
Yes
</td>
</tr>
<tr id="Port-name">
<td><code>name</code></td>
<td><code>string</code></td>
<td>
<p>Label assigned to the port.</p>

</td>
<td>
Yes
</td>
</tr>
</tbody>
</table>
</section>
<h2 id="ServerTLSSettings">ServerTLSSettings</h2>
<section>
<table class="message-fields">
<thead>
<tr>
<th>Field</th>
<th>Type</th>
<th>Description</th>
<th>Required</th>
</tr>
</thead>
<tbody>
<tr id="ServerTLSSettings-https_redirect">
<td><code>httpsRedirect</code></td>
<td><code>bool</code></td>
<td>
<p>If set to true, the load balancer will send a 301 redirect for
all http connections, asking the clients to use HTTPS.</p>

</td>
<td>
No
</td>
</tr>
<tr id="ServerTLSSettings-mode">
<td><code>mode</code></td>
<td><code><a href="#ServerTLSSettings-TLSmode">TLSmode</a></code></td>
<td>
<p>Optional: Indicates whether connections to this port should be
secured using TLS. The value of this field determines how TLS is
enforced.</p>

</td>
<td>
No
</td>
</tr>
<tr id="ServerTLSSettings-server_certificate">
<td><code>serverCertificate</code></td>
<td><code>string</code></td>
<td>
<p>REQUIRED if mode is <code>SIMPLE</code> or <code>MUTUAL</code>. The path to the file
holding the server-side TLS certificate to use.</p>

</td>
<td>
No
</td>
</tr>
<tr id="ServerTLSSettings-private_key">
<td><code>privateKey</code></td>
<td><code>string</code></td>
<td>
<p>REQUIRED if mode is <code>SIMPLE</code> or <code>MUTUAL</code>. The path to the file
holding the server&rsquo;s private key.</p>

</td>
<td>
No
</td>
</tr>
<tr id="ServerTLSSettings-ca_certificates">
<td><code>caCertificates</code></td>
<td><code>string</code></td>
<td>
<p>REQUIRED if mode is <code>MUTUAL</code> or <code>OPTIONAL_MUTUAL</code>. The path to a file
containing certificate authority certificates to use in verifying a presented
client side certificate.</p>

</td>
<td>
No
</td>
</tr>
<tr id="ServerTLSSettings-credential_name">
<td><code>credentialName</code></td>
<td><code>string</code></td>
<td>
<p>For gateways running on Kubernetes, the name of the secret that
holds the TLS certs including the CA certificates. Applicable
only on Kubernetes. An Opaque secret should contain the following
keys and values: <code>key: &lt;privateKey&gt;</code> and <code>cert: &lt;serverCert&gt;</code>.
For mutual TLS, <code>cacert: &lt;CACertificate&gt;</code> and <code>crl: &lt;CertificateRevocationList&gt;</code>
can be provided in the same secret or a separate secret named <code>&lt;secret&gt;-cacert</code>.
A TLS secret for server certificates with an additional <code>tls.ocsp-staple</code> key
for specifying OCSP staple information, <code>ca.crt</code> key for CA certificates
and <code>ca.crl</code> for certificate revocation list is also supported.
Only one of server certificates and CA certificate
or credentialName can be specified.</p>

</td>
<td>
No
</td>
</tr>
<tr id="ServerTLSSettings-subject_alt_names">
<td><code>subjectAltNames</code></td>
<td><code>string[]</code></td>
<td>
<p>A list of alternate names to verify the subject identity in the
certificate presented by the client.</p>

</td>
<td>
No
</td>
</tr>
<tr id="ServerTLSSettings-verify_certificate_spki">
<td><code>verifyCertificateSpki</code></td>
<td><code>string[]</code></td>
<td>
<p>An optional list of base64-encoded SHA-256 hashes of the SPKIs of
authorized client certificates.
Note: When both verify_certificate_hash and verify_certificate_spki
are specified, a hash matching either value will result in the
certificate being accepted.</p>

</td>
<td>
No
</td>
</tr>
<tr id="ServerTLSSettings-verify_certificate_hash">
<td><code>verifyCertificateHash</code></td>
<td><code>string[]</code></td>
<td>
<p>An optional list of hex-encoded SHA-256 hashes of the
authorized client certificates. Both simple and colon separated
formats are acceptable.
Note: When both verify_certificate_hash and verify_certificate_spki
are specified, a hash matching either value will result in the
certificate being accepted.</p>

</td>
<td>
No
</td>
</tr>
<tr id="ServerTLSSettings-min_protocol_version">
<td><code>minProtocolVersion</code></td>
<td><code><a href="#ServerTLSSettings-TLSProtocol">TLSProtocol</a></code></td>
<td>
<p>Optional: Minimum TLS protocol version. By default, it is <code>TLSV1_2</code>.
TLS protocol versions below TLSV1_2 require setting compatible ciphers with the
<code>cipherSuites</code> setting as they no longer include compatible ciphers.</p>
<p>Note: Using TLS protocol versions below TLSV1_2 has serious security risks.</p>

</td>
<td>
No
</td>
</tr>
<tr id="ServerTLSSettings-max_protocol_version">
<td><code>maxProtocolVersion</code></td>
<td><code><a href="#ServerTLSSettings-TLSProtocol">TLSProtocol</a></code></td>
<td>
<p>Optional: Maximum TLS protocol version.</p>

</td>
<td>
No
</td>
</tr>
<tr id="ServerTLSSettings-cipher_suites">
<td><code>cipherSuites</code></td>
<td><code>string[]</code></td>
<td>
<p>Optional: If specified, only support the specified cipher list.
Otherwise default to the default cipher list supported by Envoy
as specified <a href="https://www.envoyproxy.io/docs/envoy/latest/api-v3/extensions/transport_sockets/tls/v3/common.proto">here</a>.
The supported list of ciphers are:</p>
<ul>
<li><code>ECDHE-ECDSA-AES128-GCM-SHA256</code></li>
<li><code>ECDHE-RSA-AES128-GCM-SHA256</code></li>
<li><code>ECDHE-ECDSA-AES256-GCM-SHA384</code></li>
<li><code>ECDHE-RSA-AES256-GCM-SHA384</code></li>
<li><code>ECDHE-ECDSA-CHACHA20-POLY1305</code></li>
<li><code>ECDHE-RSA-CHACHA20-POLY1305</code></li>
<li><code>ECDHE-ECDSA-AES128-SHA</code></li>
<li><code>ECDHE-RSA-AES128-SHA</code></li>
<li><code>ECDHE-ECDSA-AES256-SHA</code></li>
<li><code>ECDHE-RSA-AES256-SHA</code></li>
<li><code>AES128-GCM-SHA256</code></li>
<li><code>AES256-GCM-SHA384</code></li>
<li><code>AES128-SHA</code></li>
<li><code>AES256-SHA</code></li>
<li><code>DES-CBC3-SHA</code></li>
</ul>

</td>
<td>
No
</td>
</tr>
</tbody>
</table>
</section>
<h2 id="ServerTLSSettings-TLSmode">ServerTLSSettings.TLSmode</h2>
<section>
<p>TLS modes enforced by the proxy</p>

<table class="enum-values">
<thead>
<tr>
<th>Name</th>
<th>Description</th>
</tr>
</thead>
<tbody>
<tr id="ServerTLSSettings-TLSmode-PASSTHROUGH">
<td><code>PASSTHROUGH</code></td>
<td>
<p>The SNI string presented by the client will be used as the
match criterion in a VirtualService TLS route to determine
the destination service from the service registry.</p>

</td>
</tr>
<tr id="ServerTLSSettings-TLSmode-SIMPLE">
<td><code>SIMPLE</code></td>
<td>
<p>Secure connections with standard TLS semantics. In this mode
client certificate is not requested during handshake.</p>

</td>
</tr>
<tr id="ServerTLSSettings-TLSmode-MUTUAL">
<td><code>MUTUAL</code></td>
<td>
<p>Secure connections to the downstream using mutual TLS by
presenting server certificates for authentication.
A client certificate will also be requested during the handshake and
at least one valid certificate is required to be sent by the client.</p>

</td>
</tr>
<tr id="ServerTLSSettings-TLSmode-AUTO_PASSTHROUGH">
<td><code>AUTO_PASSTHROUGH</code></td>
<td>
<p>Similar to the passthrough mode, except servers with this TLS
mode do not require an associated VirtualService to map from
the SNI value to service in the registry. The destination
details such as the service/subset/port are encoded in the
SNI value. The proxy will forward to the upstream (Envoy)
cluster (a group of endpoints) specified by the SNI
value. This server is typically used to provide connectivity
between services in disparate L3 networks that otherwise do
not have direct connectivity between their respective
endpoints. Use of this mode assumes that both the source and
the destination are using Istio mTLS to secure traffic.</p>

</td>
</tr>
<tr id="ServerTLSSettings-TLSmode-ISTIO_MUTUAL">
<td><code>ISTIO_MUTUAL</code></td>
<td>
<p>Secure connections from the downstream using mutual TLS by
presenting server certificates for authentication.  Compared
to Mutual mode, this mode uses certificates, representing
gateway workload identity, generated automatically by Istio
for mTLS authentication. When this mode is used, all other
fields in <code>TLSOptions</code> should be empty.</p>

</td>
</tr>
<tr id="ServerTLSSettings-TLSmode-OPTIONAL_MUTUAL">
<td><code>OPTIONAL_MUTUAL</code></td>
<td>
<p>Similar to MUTUAL mode, except that the client certificate
is optional. Unlike SIMPLE mode, A client certificate will
still be explicitly requested during handshake, but the client
is not required to send a certificate. If a client certificate
is presented, it will be validated. ca_certificates should
be specified for validating client certificates.</p>

</td>
</tr>
</tbody>
</table>
</section>
<h2 id="ServerTLSSettings-TLSProtocol">ServerTLSSettings.TLSProtocol</h2>
<section>
<p>TLS protocol versions.</p>

<table class="enum-values">
<thead>
<tr>
<th>Name</th>
<th>Description</th>
</tr>
</thead>
<tbody>
<tr id="ServerTLSSettings-TLSProtocol-TLS_AUTO">
<td><code>TLS_AUTO</code></td>
<td>
<p>Automatically choose the optimal TLS version.</p>

</td>
</tr>
<tr id="ServerTLSSettings-TLSProtocol-TLSV1_0">
<td><code>TLSV1_0</code></td>
<td>
<p>TLS version 1.0</p>

</td>
</tr>
<tr id="ServerTLSSettings-TLSProtocol-TLSV1_1">
<td><code>TLSV1_1</code></td>
<td>
<p>TLS version 1.1</p>

</td>
</tr>
<tr id="ServerTLSSettings-TLSProtocol-TLSV1_2">
<td><code>TLSV1_2</code></td>
<td>
<p>TLS version 1.2</p>

</td>
</tr>
<tr id="ServerTLSSettings-TLSProtocol-TLSV1_3">
<td><code>TLSV1_3</code></td>
<td>
<p>TLS version 1.3</p>

</td>
</tr>
</tbody>
</table>
</section>
